The use of fluidized systems wherein a fluidized stream is formed of finely divided coal particles, heated coke particles and a carrier stream to pyrolyze the coal particles to extract the volatiles therefrom is well known in the art. In such prior art processes the heated coke particles and/or the gas stream are utilized to provide the requisite heat of pyrolysis to the coal particles with a supply of coke continuously being produced upon pyrolysis of the coal in the system. Such systems are ideally suited to the production of coke from coal, since they are continuous processes, requiring relatively low capital outlays and can process large volumes of coal cheaply. Exemplary of such type processes is that disclosed in the U.S. Pat. No. 2,608,526 entitled "Coking of Carbonaceous Fuels" issued to W. A. Rex on Aug. 26, 1952.
However, when such prior art processes have been applied to agglomerative bituminous coal, problems have arisen due to the agglomerative nature of such coal. The agglomeration of the coal particles causes severe blockages in the system and renders the system inoperable. In recognition of the severity of this problem, the inventors in the U.S. Pat. No. 2,955,077 entitled "Fluidized Carbonization Process for Agglomerative Coals" issued to J. H. Welinsky, Oct. 4, 1960 and U.S. Pat. No. 3,375,175 entitled "Pyrolysis of Coal" issued to R. T. Eddinger, Mar. 26, 1968 disclose the use of a pretreatment of particulate agglomerative coal to lessen the deleterious effects of agglomeration. In these processes the agglomerative particulate coal is preheated in a conventional fluidized bed at temperatures ranging from 600.degree. F. to 825.degree. F. for periods ranging from 1 to 30 minutes to remove at least a portion of the volatiles from the coal so that the coal can be further pyrolyzed to recover the volatiles therefrom. The requirement of preheating agglomerative bituminous coals in these processes for relatively long residence times imposes severe economic limitations on these processes.